阅读说明：本技术 无桩基单层地下车库抗浮施工方法 (Anti-floating construction method for single-layer underground garage without pile foundation ) 是由 尹亮 汤敬 李官兵 蔡海华 其他发明人请求不公开姓名 于 2021-07-09 设计创作，主要内容包括：本发明公开了一种无桩基单层地下车库抗浮施工方法,其特征是：施工工艺流程：渗井施工——降水——土方开挖——地下室底板施工——地下室结构施工——沉降及水位观测——防水施工——防护层等施工——回填土加载——绿化种植——渗井封堵。本发明施工方便,施工周期短。(The invention discloses an anti-floating construction method of a pile-foundation-free single-layer underground garage, which is characterized by comprising the following steps of: the construction process flow comprises the following steps: seepage well construction, precipitation, earthwork excavation, basement bottom plate construction, basement structure construction, settlement and water level observation, waterproof construction, construction of protective layers and the like, backfill soil loading, greening planting and seepage well plugging. The invention has convenient construction and short construction period.)

1. An anti-floating construction method of a pile-foundation-free single-layer underground garage is characterized by comprising the following steps: the construction process flow comprises the following steps:

seepage well construction, precipitation, earthwork excavation, basement bottom plate construction, basement structure construction, settlement and water level observation, waterproof construction, construction of protective layers and the like, backfill soil loading, greening planting and seepage well plugging;

the operation key points are as follows:

(1) seepage well construction

The well pipe is made of concrete pipe with diameter of 300mm and length of 20m, the water filtering pipe is sand-free concrete pipe, the periphery of the water filtering pipe is filled with crushed stone coarse sand with thickness of 3-15mm as a filtering layer, and the water filtering pipe is backfilled with clay within 0.5m from the ground and tamped; after the well is formed, a deep well submersible pump with the lift of 50T/h40m and a water pumping pipe are put into the well, and are discharged into a drainage pipeline by a phi 75 drainage pipe, and then are discharged into a municipal pipe network after being precipitated;

(2) backfill loading

When the construction of the basement structure is finished, the strength of the structure and the construction of a waterproof layer protective layer are calculated according to the upper limit of the underground water level, the basement is guaranteed not to float upwards due to the buoyancy of underground water, and backfill is guaranteed to be thick, so that layered backfill is carried out;

calculating the thickness of the backfill soil layer:

the natural elevation of the field is equivalent to the absolute elevation plus 5.000

The upper pole of the underground water level is high: equivalent to absolute elevation +4.300

Elevation of the foundation bottom: equivalent to absolute elevation +0.450

Thickness of the bottom plate: 0.500m (reduced average thick base)

Top plate and thick bottom: 0.280m (reduced average thick base)

When the construction of the basement structure is completed, the calculation is carried out according to the upper limit of the underground water level, and the buoyancy force borne by the underground garage is as follows: calculated as 1 square meter

F_{Floating body}＝H*γ_{Water (W)}

＝(4.30-0.45)*1000

＝3850kg

In the formula F_{Floating body}Buoyancy

H-height of underground garage immersed below water level

γ_{Water (W)}Specific gravity of Water

The basement structure dead weight:

G＝(h1+h2)*γ_{concrete and its production method}

＝(0.50+0.28)*2500

＝1950kg

G-underground garage dead weight

h 1-thickness converted from underground garage foundation

h 2-thickness converted from underground garage roof

γ_{Concrete and its production method}Specific gravity of reinforced concrete

Guarantee that the basement does not come up because of groundwater buoyancy, backfill thickness:

the safety factor k is 1.15 without considering the favorable factors such as the adsorption force and the friction force between the basement and the earthwork

h＝k(F_{Floating body}-G)/γ_{Soil for soil}

＝1.15*(3850-1950)/2000

＝1.14m

K-type safety system

F_{Floating body}Buoyancy

G-underground garage dead weight

γ_{Concrete and its production method}Specific gravity of soil

The thickness of the on-site backfill is 1.20m, and is less than the design thickness of the final backfill by 1.50m, so that the anti-floating requirement is met.

Technical Field

The invention relates to an anti-floating construction method of a pile-foundation-free single-layer underground garage.

Background

The existing pile-foundation-free single-layer underground garage anti-floating construction is complex in construction, high in cost and long in construction period, and needs to be further improved.

Disclosure of Invention

The invention aims to provide the anti-floating construction method of the pile-foundation-free single-layer underground garage, which is convenient to construct and short in construction period.

The technical solution of the invention is as follows:

an anti-floating construction method of a pile-foundation-free single-layer underground garage is characterized by comprising the following steps: the construction process flow comprises the following steps:

seepage well construction, precipitation, earthwork excavation, basement bottom plate construction, basement structure construction, settlement and water level observation, waterproof construction, construction of protective layers and the like, backfill soil loading, greening planting and seepage well plugging;

the operation key points are as follows:

(1) seepage well construction

The well pipe is made of concrete pipe with diameter of 300mm and length of 20m, the water filtering pipe is sand-free concrete pipe, the periphery of the water filtering pipe is filled with crushed stone coarse sand with thickness of 3-15mm as a filtering layer, and the water filtering pipe is backfilled with clay within 0.5m from the ground and tamped; after the well is formed, a deep well submersible pump with the lift of 50T/h40m and a water pumping pipe are put into the well, and are discharged into a drainage pipeline by a phi 75 drainage pipe, and then are discharged into a municipal pipe network after being precipitated;

(2) backfill loading

When the construction of the basement structure is finished, the strength of the structure and the construction of a waterproof layer protective layer are calculated according to the upper limit of the underground water level, the basement is guaranteed not to float upwards due to the buoyancy of underground water, and backfill is guaranteed to be thick, so that layered backfill is carried out;

calculating the thickness of the backfill soil layer:

the natural elevation of the field is equivalent to the absolute elevation plus 5.000

The upper pole of the underground water level is high: equivalent to absolute elevation +4.300

Elevation of the foundation bottom: equivalent to absolute elevation +0.450

Thickness of the bottom plate: 0.500m (reduced average thick base)

Top plate and thick bottom: 0.280m (reduced average thick base)

When the construction of the basement structure is completed, the calculation is carried out according to the upper limit of the underground water level, and the buoyancy force borne by the underground garage is as follows: calculated as 1 square meter

F_{Floating body}＝H*γ_{Water (W)}

＝(4.30-0.45)*1000

＝3850kg

In the formula F_{Floating body}Buoyancy

H-height of underground garage immersed below water level

γ_{Water (W)}Specific gravity of Water

The basement structure dead weight:

G＝(h1+h2)*γ_{concrete and its production method}

＝(0.50+0.28)*2500

＝1950kg

G-underground garage dead weight

h 1-thickness converted from underground garage foundation

h 2-thickness converted from underground garage roof

γ_{Concrete and its production method}Specific gravity of reinforced concrete

Guarantee that the basement does not come up because of groundwater buoyancy, backfill thickness:

the safety factor k is 1.15 without considering the favorable factors such as the adsorption force and the friction force between the basement and the earthwork

h＝k(F_{Floating body}-G)/γ_{Soil for soil}

＝1.15*(3850-1950)/2000

＝1.14m

K-type safety system

F_{Floating body}Buoyancy

G-underground garage dead weight

γ_{Concrete and its production method}Specific gravity of soil

The thickness of the on-site backfill is 1.20m, and is less than the design thickness of the final backfill by 1.50m, so that the anti-floating requirement is met.

The invention has the advantages that:

1. the construction investment is reduced, the construction pile foundation generally occupies five percent of the construction cost, and the pile foundation is omitted, so that the construction cost is reduced.

2. Construction convenience has been cancelled the pile foundation, and the foundation slab does not have the cushion cap, has saved processes such as pile, broken pile head, construction cushion cap, and the foundation slab structure has been simple, has brought the facility for the construction.

3. The construction period is shortened, and compared with the traditional engineering adopting pile pulling resistance, the construction period is shortened greatly because the work of pile testing, pile driving, detection, pile bearing platform construction and the like is not required.

4. After the underground garage is structurally backfilled with soil, the greening lawn is planted, so that the construction environment is beautified, and the method has practical significance for green construction and achieving 'four sections and one environment protection'.

The present invention will be further described with reference to the following examples.

Detailed Description

An anti-floating construction method of a pile-foundation-free single-layer underground garage comprises the following construction process flows:

seepage well construction, precipitation, earthwork excavation, basement bottom plate construction, basement structure construction, settlement and water level observation, waterproof construction, construction of protective layers and the like, backfill soil loading, greening planting and seepage well plugging;

the operation key points are as follows:

(1) seepage well construction

The well pipe is made of concrete pipe with diameter of 300mm and length of 20m, the water filtering pipe is sand-free concrete pipe, the periphery of the water filtering pipe is filled with crushed stone coarse sand with thickness of 3-15mm as a filtering layer, and the water filtering pipe is backfilled with clay within 0.5m from the ground and tamped; after the well is formed, a deep well submersible pump with the lift of 50T/h40m and a water pumping pipe are put into the well, and are discharged into a drainage pipeline by a phi 75 drainage pipe, and then are discharged into a municipal pipe network after being precipitated;

(2) backfill loading

When the construction of the basement structure is finished, the strength of the structure and the construction of a waterproof layer protective layer are calculated according to the upper limit of the underground water level, the basement is guaranteed not to float upwards due to the buoyancy of underground water, and backfill is guaranteed to be thick, so that layered backfill is carried out;

calculating the thickness of the backfill soil layer:

the natural elevation of the field is equivalent to the absolute elevation plus 5.000

The upper pole of the underground water level is high: equivalent to absolute elevation +4.300

Elevation of the foundation bottom: equivalent to absolute elevation +0.450

Thickness of the bottom plate: 0.500m (reduced average thick base)

Top plate and thick bottom: 0.280m (reduced average thick base)

When the construction of the basement structure is completed, the calculation is carried out according to the upper limit of the underground water level, and the buoyancy force borne by the underground garage is as follows: calculated as 1 square meter

F_{Floating body}＝H*γ_{Water (W)}

＝(4.30-0.45)*1000

＝3850kg

In the formula F_{Floating body}Buoyancy

H-height of underground garage immersed below water level

γ_{Water (W)}Specific gravity of Water

The basement structure dead weight:

G＝(h1+h2)*γ_{concrete and its production method}

＝(0.50+0.28)*2500

＝1950kg

G-underground garage dead weight

h 1-thickness converted from underground garage foundation

h 2-thickness converted from underground garage roof

γ_{Concrete and its production method}Specific gravity of reinforced concrete

Guarantee that the basement does not come up because of groundwater buoyancy, backfill thickness:

the safety factor k is 1.15 without considering the favorable factors such as the adsorption force and the friction force between the basement and the earthwork

h＝k(F_{Floating body}-G)/γ_{Soil for soil}

＝1.15*(3850-1950)/2000

＝1.14m

K-type safety system

F_{Floating body}Buoyancy

G-underground garage dead weight

γ_{Concrete and its production method}Specific gravity of soil

The thickness of the on-site backfill is 1.20m, and is less than the design thickness of the final backfill by 1.50m, so that the anti-floating requirement is met.